U.S. Pat. No. 5,247,083 to Martin Knox et al. disclosed a process for making mycophenolate mofetil by refluxing mycophenolic acid with 2-morpholinoethanol in an inert organic solvent even without the use of catalyst. However, the reaction requires a long time period. For example, when the reaction completion was 94.9% by refluxing the reaction mixture at 125˜129° C., it already consumed 63 hours. The long reaction time may increase the production cost and may also waste energy when heating the reaction mixture for such a long time period.
The present inventor has found the drawbacks of the conventional process and invented the present process for making mycophenolate mofetil by shortening the reaction time in order to reduce the production cost and improve the product purity.